maint: Use space after function name/before parenthesis in libgui. * Backend.cc, ButtonControl.cc, ButtonGroup.cc, Canvas.cc, Container.cc, EditControl.cc, GLCanvas.cc, ListBoxControl.cc, ListBoxControl.h, PopupMenuControl.cc, QtHandlesUtils.cc, TextControl.cc, TextEdit.h, annotation-dialog.cc, annotation-dialog.h, gl-select.cc, dialog.cc, files-dock-widget.cc, find-files-dialog.cc, history-dock-widget.cc, file-editor-tab.cc, file-editor.cc, file-editor.h, find-dialog.cc, marker.cc, octave-qscintilla.cc, octave-qscintilla.h, main-window.cc, octave-dock-widget.cc, octave-dock-widget.h, octave-gui.cc, parser.cc, parser.h, webinfo.cc, settings-dialog.cc, shortcut-manager.cc, welcome-wizard.cc, workspace-view.cc: Use space after function name and before parenthesis.

--- a/libgui/graphics/ButtonControl.cc	Wed Jan 18 17:48:32 2017 -0500
+++ b/libgui/graphics/ButtonControl.cc	Wed Jan 18 17:36:36 2017 -0800
@@ -126,8 +126,7 @@
         Matrix oldValue = up.get_value ().matrix_value ();
         double newValue = (checked ? up.get_max () : up.get_min ());
 
-        if (oldValue.numel() != 1
-            || (newValue != oldValue(0)))
+        if (oldValue.numel () != 1 || (newValue != oldValue(0)))
           gh_manager::post_set (m_handle, "value", newValue, false);
         gh_manager::post_callback (m_handle, "callback");
       }